The first
seven signals were received near
Düren, Germany in a small village. The
receiver was located only 15 meters
away from the village mains supply
transformer in these cases, which
explains the good quality of the
received signals. The described sounds
refer in (in all cases) to a playback
160 times faster than the original
signal. If not indicated, all the
signals were recorded by coil.

01 GOOSE

Received
permanently day and night from 2002 until 2009 in an
area of 40 kilometers of diameter. The source seemed
to be located in the northern Eifel region in
Germany. The signal consists of bursts of 16 Hz sine
signals and begins with a kind of header. Then
something like an address code is following where
one burst of a fixed number of usually eleven or
twelve bursts is missing. After that, an
irregular pattern of four or five bursts is
following. The signal repeats irregularly within 24
hours, but this irregular pattern was usually
repeated each day. The signal was so strong that it
could even be heard in real time as a loud hum via
an ordinary guitar amplifier.

Received
permanently day and night from 2002 until 2006.
There were two sources sounding similar but
differing in their pitch a little. The signals came
regular and independent from each other but the
pauses between two signals differed from day to day.
The spectrum shows a very low and dense line
structure reminding at (and sounding like) a ramp
signal.

Received each day for
two to four hours at irregular start times. The signal
is characterized by sequences of sine waves mixed with
a noise which change their frequency stepwise. The
pattern is separated in groups of 12 to 13 steps. In
the pauses it sounds like as if another station would
“reply”. Similar signals could be received from time
to time until today in different parts of Germany.

Very strong signal
appearing from the beginning of 2004. This signal now
can be received everywhere in Germany and probably
also in the neighbour countries, coming from a lot of
different sources and appearing only at (irregular)
daytimes. The FFT vs. Time of the signal structure
looks nearly like a symmetrical square wave. The time
signal shows a sequence of positive and negative peaks
which indicates the influence of a coil or a
capacitor. The length of the signal period is about
0.62 seconds.

This signal only
appeared in January 2004. It was received never before
and never after and sounds exactly like an old
fashioned needle printer, showing also a very complex
time and FFT signal that indicates some kind of data
transfer.

This signal also was
present only for a short time (recording time not
documented but between 2003 and 2006). It sounds like
an old computer modem or a RTTY radio teletype signal
on shortwave. Similar signals could be recorded at
some times in different places in Germany.

Recorded from 2006
until 2010 in the region of Alsdorf, Germany. The
given example is a collection of the most interesting
signals sounding like a robot voice. Each night most
of the time only a few “words” could be received after
pauses of some hours.

This signal really
sounds like an RTTY shortwave signal: A sine carrier
jumps between to constant frequencies. The signal
could be recorded day and night over the weekend in
2008 in a hotel room as well as at the hotels parking
lot in a small village near the German town
Saarbrücken.

This sound was also
recorded near Saarbrücken in the year 2005 (over
night) in a private house at the border of a forest.
Similar signals can be recorded since 2009 at the
authors home Alsdorf via earth probes.

The
foghorn signal is partly comparable to the cow signal
could be received in Alsdorf at the authors home since
2006. The signal can be received by coil and by
probes. At some months, it is very strong and at other
months it is completely gone (like at the moment since
two months)..

This strange recorded
sound can also be produced by modulating a sine wave
oscillator by another one in its frequency while
changing the frequencies permanently. These kind of
signals (they are never completely the same) appear
extremely rare and at different places.

Sounds a little like the
horn of a bypassing truck on a highway. This signal
until now only could be registered in Alsdorf since two
years and appears a few times within 24 hours at day and
sometimes at night too.

Very
interesting signal which sounds like a flute and which
only can be recorded with earth probes and only at the
author’s garden. The signal appeared the first time in
January 2011 and was so strong that the receiver was
nearly overdriven. The frequency is very low and goes
from below one up to 5 Hz. The typical signal pattern is
a “base line” which is permanently present. From this
base line, the tones are mounting in constant and
harmonic steps (notes) up or down and returning again to
the base line as shown in the example. Sometimes the
pattern is regular and sometimes irregular. Sometimes,
the frequency of the base line is changing. The signal
vanished a few months later and came back in 2013, but
not as strong as before. In addition, the frequency is
not stable but kind of “shaky”, as if someone would use
a generator driven by muscle power. Since a few weeks,
the signal got lower and lower in its level and now
seems to vanish completely behind the natural noise.

Recording made in 2004
in a village near Saarbrücken in a private house in a
living area at the border of a forest (15 kilometers
from the place where the night owl was recorded). The
typical sequence of sine wave tones mounting and falling
in constant steps reminds me of the sound of a pan
flute.

It’s hard to find any
natural sound comparable to this, but it reminds me a
little of the pan flute. It’s only a little more
complex. In the FFT vs. Time we also can see a complex
pattern of parallel sine waves changing stepwise their
frequency. This signal is very rare and only can be
detected by probes at the author’s home since 2009.

This signal appears at
the author’s home from afternoon to approximately 9 or
10 pm since one year and seems to get longer and longer
by time. The frequency of a sine wave signal seems to
mount from zero to a few hertz and then falling and
mounting again periodically. The small hooks sometimes
appearing make the whole spectrogram look like a
ramp-factory roof with chimneys.